Problem: Evaluate the following expression when $a = 10$ and $b = 3$. $8$ $a$ $ + 4$ $b$ $ - 7$
Solution: Substitute $10$ for ${a}$ and $3$ for ${b}$ $ = 8{(10)} + 4{(3)} - 7 $ $ = 80 + 12 - 7 $ $ = 85$